The path to the Gemfile for the app. Example: BUNDLE_GEMFILE:/home/vcap/app/Gemfile

BUNDLE_WITHOUT

Instructs Cloud Foundry to skip gem installation in excluded groups. Use this with Rails applications, where “assets” and “development” gem groups
typically contain gems that are not needed when the app runs in production. Example: BUNDLE_WITHOUT=assets

DATABASE_URL

Cloud Foundry examines the database_uri for bound services to see if they match known database types. If known relational database services are bound to the app, then the DATABASE_URL environment variable is set to the first services in the list.

If your application requires that DATABASE_URL is set to the connection string for your service, and Cloud Foundry does not set it, use the Cloud Foundry Command Line Interface (cf CLI) cf set-env command to set this variable manually. Example:

The directory where gems are installed. Example: GEM_HOME:/home/vcap/app/vendor/bundle/ruby/1.9.1

GEM_PATH

The directory where gems can be found. Example: GEM_PATH=/home/vcap/app/vendor/bundle/ruby/1.9.1:

RACK_ENV

The Rack deployment environment, which governs the middleware loaded to run the app. Valid value are development, deployment, and none. Example: RACK_ENV=none

RAILS_ENV

The Rails deployment environment, which controls which environment-specific configuration file governs how the app is executed. Valid value are development, test, and production. Example: RAILS_ENV=production